Chusetts



(No Model.) 2 Sheets- Sheet; 1. L. MELLETT & J. FRINGE.

' ELECTRIC ORE INDICATOR.

N0. 367,541. Y Patented Aug. 2, 1887.

(No Model.) I 2 Sheets-Sheet 2. L. MELLETT & J. PRINCE.

ELECTRIC ORE INDICATOR.

No; 367,541. Patented Aug. 261887.

UIIIIIMI UNITED STATES PAT NT OFFICE.

LEMUEL MELLETT AND JEROME PRINCE, OF MILFORD, ASSIGNORS TO SAID LEMUEL MELLETT, AND GEORGE REED, OF FITOHBURG, MASSA- OHUSETTS.

ELECTRIC ORE-INDICATCR.

SPECIFICATION forming part of Letters Patent No. 367,541, dated August 2, 1887.

Application filed March 24, 1886.

Serial No. 196,353. (No model.)

To all whom it may concern:

Be it known that we, LEMUEL MELLETT and JEROME PRINCE, both of Milford, county of Worcester and State of Massachusettahave invented an Improvement in Electrical Indicators, of which the fpllowing description, in connection with the accompanying drawings,

is a specification, like letters on the drawings representing like parts. I This invention has for its object to provide apparatus by 'which the presence of mineral ores or metallic substances either on or below the surface of the earth or under water may be indicated.

Our invention is especially adapted to be used in locating veins or deposits of mineral ores in the earth and also for the detection of metallic substances under water.

The particular features of our invention will be pointed out in the claims at the end of this specification.

Figure 1 is a top view of a case containing the apparatus by which to practice our invention. Fig. '2 is a vertical section of Fig. 1 in theline a: a, through the indicator or galva nometer; Fig. 3, a longitudinal section of one of the terminal electrodes, and Fig. 4 a diagram of the circuits to more clearly illustrate the working of the apparatus. Y

7 the plugs a a, when it is desired to place the battery in circuit. y

The cover A supports a vertical indicator or galvanoineter, a, having a case, a secured by screws a to the cover A, the said indicator or galvanometer having a pointer or needle, a located outside the wire coils, and an armature, a, mounted on the needle shaft or arbor a within the coils, the said. indicator or galvanolneter being included .in circuit with the battery.

The cover A of the case, which may be of The armature a, as herein shown, is composed of a star-shaped piece of soft iron which has been hardened and then charged in any well-known manner to form a permanent magnet, the points of the star forming three con- 5 I is connected to the plug (0, (shown in Fig. 1,)

the said plug being represented in Fig. 4 as the negative pole of the battery, and the second wire,b,to one member, N, of a switch, the other member of which is a pivoted lever, b connected by a wire, I)", to a post, b of an ordinary telegraph-key, 13, located upon the cover of the box. A second post, I), of the key B is joined to a pivoted lever, 12 forming onemember ofa switch,the cooperating memher I) of which is connected by wire I)" to the plug a ,(shown in Fig. 1,) and which isrcpresented in Fig. 4 by the positive pole of the battery. p

The indicator or galvanometer a is placed upon the cover A, so that its needle a will revolve in aplane at right angles to said cover. The cover A also supports a galvanometer in circuit with the battery referred to, and is herein shown as marked to indicate points of the compass, said galvanometer having one of its wires, 0, fastened to one member, 0, of a switch, the co-operating member of which is the leverb and having its other wire, 0 joined to the wire I), connected with .the plug a (shown in Fig.1,) and which in Fig. 4 is represented by the negative pole of the battery.

Secured to the cover A are two bindingposts, (1 d, the post (I being connected by the wire d to the wire I), (see Fig. 4,) and the post d by wire d to'the switch member 0 in the branch circuit.

WVhen it is desired to employ the apparatus to indicate the presence of mineral ores or deposits near the earths surface, the lever b will be turned, so as to co-operate with the member 0 and thus place the galvanometer c 100 in circuit, the said galvanometer being substantially at right angles to the indicator or galvanometer a which circuit may be traced in Fig. 4 from the positive pole of the battery 5 by wire 11", lever 1), wire 0", to post 1;, through the metallic frame of the key, lever b, and anvil I), (see Fig. 1,) to post If, from thence by wire Z), lever 1), member 0*, wire 0, through the galvanometer 0, wires 0" and b, to the nega- IO tive pole of thebattery. \Vith the galvanometer c in circuit the apparatus is carried by the operator as he walks over the ground or territory to be examined, and the key 13 is worked to cause the galvanometerneedle to 15 be revolved.

By experiment it has been found that when the apparatus is brought in the vicinity of mineral ores or deposits the influence of said ores upon the galvanometer-needle is such as to stop or retard to a considerable degree the revolution of said needle, thus indicating the presence ofa mineral, notwithstanding the fact that the key is being constantly worked.

lVhen it is desired to indicate the presence of veins of mineral ores in a mine, shaft, or tunnel, it has been ascertained by experiment that the galvanometer 0 used for surface indications does not work advantageously, and for this purpose the indicator or galvanometer a,

placed at right angles to the galvanometer c,is

employed.

\Vhen it is desired to employ the apparatus in a shaft or mine, the lever b will be turned from its dotted to its full line position shown 5 in Fi 4, thereby cutting out of circuit the galvanometer c and placing in circuit the indicator or galvanometer a said circuit being the same as that described for the galvanometer c to the lever b, and said circuit is comto pleted by switch member If, line b, galvanometer a and wire b to the ncgativc 'pole of the battery.

As the apparatus is carried down the shaft or mine to be examinechthe operator varies his position, so that the galvanometer may be turned through the different points of the coinpass, and the key B is constantly worked, thus causing the armature a, and thereby the nee-' dle a to revolve; but when brought neara vein of mineral ore theintluence ofsaid mineral ore upon the armature a" is such as to stop or to a great degree retard the revolution of the needle, the latter at such time pointing in the direction of the vein. The star-shaped armature is caused to revolve by the current passing through the coils of the indicator or galvanometcr a as long as the said indicator or galvanometer is maintained in circuit with the battery and the apparatus is beyond the influonce of mineral. deposits.

It has been found by experiment, when the apparatus is brought in theivicinity of small deposits of ore, that normally the influence ol' the current upon the galvanometer-needle is greater than the influence of the said small mineral deposits, the needle under such cir on instances being continuously revolved by the batterycurrent. Under these conditions it has been found necessary to employ a resistance, R, having one end connected to the positive pole of the battery by the wire b", and being joined at its other end to the post Z) of the key. This resistance B, when switched into circuit by turning the lever b from its full to its dottcdline position, (shown in Fig. 4,) re duces the current, so that it has but little effect upon theneedle,it merely revolving the latter slowly and substantially uniformly, thus rendering the said needle sensitive to the action of very small deposits. This resistance R is also used in dry weather when it has been found that the needle is strongly affected by the current of the battery but when the weather is cloudy and the air is charged with electricity, the resistance It will then be out of circuit, because the electricity of the air acts to somewhat counteract the battery-current.

\Vhen the apparatus is employed to indicate the presence of metallic substances under wa ter or near the surface of land which is covered by water, or immediately beneath the bottom of a bay or harbor, the lever b will be turned to occupy the position marked 2, between the switch members I) 6-, and the terminal electrodes 0 0 will be placed in circuit with the galvanometer e, the electrode 0 being connected by wire 6" to the post 12, and the electrode 0 by wire 0" to the post (1, said elec trodes being separated by the insulating-block e, the circuit-closer c of the key B being closed, as shown in Fig. 4, while the said elec trodes are in use.

The electrodes 0 c are each composed of a shell or case of copper or brass or other noncorroding metal and preferably of the shape indicated, said shell consisting of two parts, 3 4, screwed together, the part 4 being cored to receive within it a permanently-charged magnet, 5, herein shown as horseshoe in shape.

The wires 0 e are designed to be of such length as will permit the electrodes cc to drag on the bottom of the harbor or bay or other sheet of water, and the circuit of the electrodes IIC will be closed when said electrodes come in contact with any metal substance, thus causing the galvanometer-needle to revolve, and said needle may be revolved even when said electrodes come in the immediate vicinity of metal substances without touching the same, the circuit being traced from the positive pole of the battery by wire b", lever b wire a", post I), circuit-closer e, to post If, wires 1), d", and 6*, to electrode 6, through the metal substance, electrode 6, wires 0, (l and 0, through the galvanometer c, and thence to the negative pole of the battery by wires 0" and 1).

We claim 1. In an electrical indicating apparatus, a box or case, a battery, a substantially vertical indicator or galvanometer carried by said case or box and provided with a pointer or needle, a pointer-shaft, and an armature mounted upon nometer, and with a resistance to reduce the strength of the battery-current and enable the galvanometer-needle to be affected by small deposits of mineral near the earths surface, and a switch to shunt the resistance out of circuit, substantially as described.

3. In an electrical indicating apparatus, a box or case, a battery, and an indicating device carried by the box or case, in circuit with the battery, combined with terminal electrodes e c, composed of a shell or case of non-corroding metal, and a permanently-charged magnet contained therein in circnit'with the indicating device, substantially as described.

4. The terminal electrodes consisting each of a shell or case of non-corroding metal, and a permanently-charged magnet located therein, substantially as described.

5. The terminal electrodes consisting each of a shell or case composed of copper or brass and cored to receive a permanent magnet, combined with the permanently-charged magnet inclosed within said shell or case, substantially as described.

In testimony whereof we have signed our names tothis specification in the presence of two subscribing witnesses.

LEMUEL MELLETT. JEROME PRINCE.

\Vitnesses: I

(3120. W. GREGORY. J. H. CHURCHILL. 

